Lifting-jack.



' l1MM4,904.

'PANN-TED DEG; 24,1907. J... HQNBURKHOLDER. v ,LIPTING JGK. 4 -APPLIUA'TIOAN FILED murx 10.51901 A TT ,RME YS Noi 874,904.

all whom it may concern: JOHN H. BURK-v UNITED STATES PATENT @FFI-QE,-

JOHN' H. BURKHOLDER, OF ASHLAND, OHIO, As'sIcNon To 'LITEMNFACTURING coMPANY,.oF ASHLAND, OHIO, A rAnTNnRsHrrLj' l' LIFTING-TACK.

'Be it` known that I, HOLDER, a citizen of the United States, residing at Ashland, -in the county of Ashland and State of Ohio, have invented certain new and useful Improvements in Lifting-f-Jacks, and do declare thatthe following is a`full, clear, and exact descri tion of the invention, which will enable 'ot 1ers skilled in the art to which it appertains to make and use the same.

My invention relates to lifting jacks, and the'invention consists 'in a lifting jack of compound construction, whereby a con tinuous operation of the jack is sustained in either direction according as it is set for movement of the lift upward or downward, all substantially as 1shown and described and particularly pointed out in the claims.

In theY accompanyino' drawings, Figure 1 is a side elevation o the jack partially brokenV away at the bottom, and Fig. 2 is a vertical sectional elevation on line 2 2, Fig. 1. Fig. 3 is a cross section on line 3 -3, Fi `1, and Fig. 4 is a sectional elevation on `ine 4-4, Fig. 1. l

This device comprises a dual or compound construction of jack, in which one side or part of the power applying lInechanism supplements the other side or part in immediate succession, so as to maintain a continuous movement of the lift member upward or downward according to its adjustments for the time beingand whereby the speed of operation is doub d over asingle acting machine, as will now more clearl appear. Thus, having reference to the rawings, the device comprises a single tubular standard A and a lift member B movable up and down in said standard. Said Ymember B is screw threaded substantially its entire length from its lower end upward and has a guide b at its lower end running in channels or ooves in said standard, whereby it is hel toa direct up and down movement and prevented from turning in the standard. A preferably rotatable head 2 is'iixed on lift member B, and a miter gear C is supported in a recess or open space in the top of the standard between arms 3 which support the extremity of the standard above said recess and gear. Said gear 1s threaded internally like a nut and engages their other ends into engagement.

p patentes n'sl e4, i907.

threaded liftiB ,to raise and -same accordingto directionfojf its, rotation.

Operation oi miter'gear C', and lthrough it the raising. of lift membe-rB,jis effected by means of tworbevel. gearslDand E, respectively, su ported oppositely on standard A on suitab e plirvot orscrewpllSQoi-fshafts 4 lever extensions. A6 onfilever': G. I-'- .;'SaidI yeX- tensions project inward from head 7 of said lever' and engage on said pins inside of gears D and E, and pawls 9 and 1() are pivoted in said head and are double acting and adapted to throw either end into working engagement with the corresponding gear according as said ear is to be turned one way or the other.' urtherrnore, said pawls are operatively mounted in the ends of head 7 on the ends of a rod or shaft 12 diagonally disposed in said head and engaged centrally with a spring pressed bolt 13 adapted to rotate in its bearings in handle G and to hold said. pawls in engaging relation whichever ends may be thrown forward for the time being, and Opposite ends of said pawls work at the Asame time, relatively as seen in Fig'. 1.

Hence both gears D and E act together successively when lever G is operated up and down at its free end, and cause gear C to rotate continuously in one direction until the parts are reversed. In this Operation iirst .one pawl will act and then the other, and the pawl idle for the moment will slide over the cogs of its wheel till the direction of handle G is reversed when it will act and the other will be idle and slide. Thus one pawl acts On the down stroke of the handle and the other on the up stroke, makin a continuous rotation of gear C, and the direction of rotation of said gear is changed when the positions of said pawls is reversed., throwing This is done by pressing the thumb against the upper disengaged end of the pawl, whichever 1t may be, when both pawls will be reversed through their connection 12. Said pawls Vhave ears 14 behind their pivots 15 through which connecting rod 12 engages, and spring'V 17 about bolt 13 normally presses upon said rod 12 and therethrough against ears 14 to hold both pawls in operative engagement with their respective gears in either of the ,eaded into-,said standard and servlng also as; pivotsupports,for handle-:or

reversible ositions of the pawls. To this end it will be noted that bolt 13 is both free to Workand slide and is located axiallyon a central line passing through the lever and pawl pivots.

What I claim is f In lifting jacks, a standard A, a lift niember B therein and a rotatable actuating gear C screwed onto said lift member and seated in the upper end of said standard, gea-rs E rotatably mounted on opposite sides of said standard adapted to rotate inopposite directions and meshing with said' actuating ear an o eratin handle .G havinT a eross` head and a substantially yoke shaped extension 6 therefor supported on opposite sides of standard A, and double engaging lplawls 9 and`10 pivoted between said crossead and extenslon 6 and adapted to engage said side gears at one or the other end according to their position, a connecting rod 12 between said pawls, a bolt 13 soeketed in the base of said cross head and having said rod 12 extending through the saine, a spring 17 about said bolt and pressing against said rod 12, and pawls having extensions outside,

J OIIN II. B URKHOLDER.

Witnesses:

flI. T. FISHER,

B. Moshe. 

